The glacier that gives life to Ganga is disappearing

On a recent trek to the mouth of the Ganga, one was surprised to see markings all along that indicated how the glacier has been receding over the years. It was shocking that despite scientific evidence that the glacier has indeed been receding over the century, very little is being done to mitigate the damage.

On a recent trek to the mouth of the Ganga, one was surprised to see markings all along that indicated how the glacier has been receding over the years. It was shocking that despite scientific evidence that the glacier has indeed been receding over the century, very little is being done to mitigate the damage.

Gaumukh is a glacier situated at an altitude of 4,023 metres. Ringing the glacier are lofty peaks, which are called the Gangotri group of mountains. These include peaks like Chaukhamba, Kedarnath, Thalay Sagar, Shivling, Meru and Bhagirathi I, II and III. Gaumukh is connected with the Gangotri temple by a foot trail, about 15 kilometres long, a popular trek among tourists, while also being a pilgrimage route since millennia.

More than half a million years ago there was an unprecedented rise in the number and intensity of glaciers in the Himalayas, which coincided with a massive tectonic movement, uplifting the crust and the upper mantle of the earth, that drove the snowline, much further south than it is today, across the lesser Himalayan ranges and the Shivaliks. This created the lofty feet of the Himadri Range, the snow-capped upper Himalayan ranges. These glaciers have been feeding the river since several centuries. It is believed that during a different part of the Holocene, before the earth’s climate became as volatile as it is today, the Gaumukh glacier must have been situated at Gangotri. It is here, at Gangotri that the sage Bhagirath is said to have practiced penance to bring the Ganga to earth.

The ice cave has now moved at least sixteen kilometres upstream. Today, the glacier may be receding, but the glacial melt is still able to lead to a perennial flow. But for how long will this flow continue is a matter to scientific prediction and should be of concern to all of us.

Legend has it that while searching for his lost sheep, a shepherd boy reached near a glacier in Gangotri, the snout of which exactly looked like the mouth of a cow, thus giving it the name Gaumukh. From then on, many saints, as well as pilgrims have considered it the mouth of the holy river. Gaumukh has been the subject of several expeditions and historic researches. Even though pilgrims and ascetics must have visited Gaumukh much before the 19th century, no records can be traced.

The first recorded visit to Gaumukh is dated May 31, 1817, by John Hodgson and James Herbert who traced the glacial origin of the river. This is what they said about what they witnessed,

A most wonderful scene, the Bhagirathi or Ganges issues from under a very low arch at the foot of the grand snow bed, the river here is bounded to the right and left by high snow and rocks, but in front the mass of snow is perfectly perpendicular, and from the bed of the summit we estimated the thickness a little less than 300 feet of solid frozen snow, probably accumulation of ages.

The early phases in the exploration of the source of the Ganga have been depicted by Colebrooke and describe the first attempts to provide a reliable map of the area, starting from China, because it was thenbelieved that the source was north of the Himalayas and that the river was several hundred kilometers longer than it actually is. One of the early maps was published in Teiffenthaler’s three volume set of a description of Hindustan. Gangotri is mentioned first by British colonial officers since Fraser visited the place as the first European in 1815. His and other reports are rather brief; Hodgson’s account is somewhat longer but for the most part only geographical. However, these reports give us a wealth of information.

After Fraser in 1815, Hodgson followed in 1817 to visit Gangotri. The geographical knowledge of the natives at that time was apparently accentuated by mythical beliefs. Thus, Skinner reports that, according to a statement of an inhabitant, the spot of confluence of Bhagirathi and Jahnavi near Bhairon Ghati, ten kilometers below Gangotri, was considered narrow enough to leap over (whereas Skinner measured sixty yards). The first European travelers did not get farther than a few hundred metres beyond the village and they report the natives’ opinion that it is impossible to venture higher.

On our trek from Gangotri to Gaumukh, we came across several markings by geologists, from the past, that pointed towards severe recession of the Gaumukh glacier. This is worrisome for the future health of the Ganga. Let us delve a little deeper into what is causing this and its effects.

Glaciers are the consequence of the ice ages. Gaumukh or Gangotri glacier cover of the Himalayas is the consequence of the Quaternary Ice Age, and geologists have reasons to believe that the ice limit may have, once, extended beyond the southern limits of the outer Himalayas. Since the last glacial cycle of the Quaternary Ice Age – about 10,000 years ago, practically every glacier has shown degeneration in mass and volume. Same is true of the Gangotri glacier also.

Gaumukh glacier is a system with a glacierized area of about three hundred square kilometres. It is situated in the Bhagirathi valley of the Uttarakhand Himalayas, and comprises a cluster of more than seven glaciers, most of which merge or flow in to the main trunk. Behaviour of this glacier, since the last glacial activity, can be better illustrated by referring to three distinct observations.

Glaciers, wherever they exist or existed, leave a distinct signature in the form of glacier landforms. These landforms can be the consequence of the glacier erosion or deposition. A survey of the Bhagirathi valley, downstream of the Gangotri temple, has revealed the existence of numerous characteristic glacier landforms like glacier pavements, saw cut trenches, link cavity system and till deposits almost up to Jangla, a linear distance of about fifty kilometres from the present snout position. Presence of so many characteristic glacier land forms leaves no doubt in one’s mind that, at one time in the past – most likely during the last phase of glacial activity 10,000 years ago – Bhagirathi valley must have been more glacierized than at present; and the Gangotri glacier must have extended at least up to Jangla.

The word Gangotri stands for Ganga + utri i.e. Ganga’s descent. The glacier has become a part of the legend that speaks of the descent of the Ganga from the heavens, and can take pride of place, though indirectly, of being the earliest explored glacier, in human history, by Bhagirath about 5,500 odd years back. In Skanda Purana, Bhagirath is quoted to have said, “Then came down from the sky, Ganga the daughter of the snowy mountains, and Mahadev (Shiva) received it (Ganga) on his own head”.

We may presume that Bhagirath was an explorer who did the journey as penance to trace the source of this mighty river. What Bhagirath may in fact have stated, when he had the view of the entire glacier from a point up in the mountains, could be, “Ganga coming from the skies frozen around the shoulders of a mighty peak that appeared like the Shivling – a personification of the Lord Shiva”. Bhagirath visualised that if the whole glacier would melt all at once, the waters so released would cause havoc down below. In fact, it would be disastrous. And he apparently stated it as such. That, in due course, became the legend that Lord Shiva held the river back in his locks lest Ganga cause the havoc. Legend further tells us that, “Ganga, when it finally managed to come out of the intricate dark locks (or moraine ridges) of Shiva which are as fearsome and large as the Himalayas itself, was still so powerful that it went down to the nether world before coming on the surface.” Bhagirath’s metaphorical reference of the Shivling peak, moraine ridges and the water fall at Gangotri clearly indicates that, at the time of Bhagirath’s visit, the snout of the Gangotri glacier must have been at and around Gangotri town. Obviously, there was no ice cave, as no mention of Gaumukh has been made, and the glacier apparently must have been in active phase. This view is held by the head priest and other holy men around the shrine of Gangotri.

Taking the three possible snout positions, and different periods of time into consideration, Jangla (10,000 years ago), Gangotri (about 5,500 years ago, based on secular retreat) and the present position at Gaumukh, it can be concluded that the glacier has vacated a total linear distance of 47 kilometres in about 10,000 years – the glacier would appear to have shown an average secular retreat of 27.5 metres per year, during the last 500 years.

Snout of the Gangotri glacier marked by the prominent ice cave has been the celebrated destination for explorers and the pilgrims over the centuries, for it is where, according to them that Ganga originates. The earliest photograph of the snout is that of Samuel Bourne published in 1863. Yet another picture of the snout of Gaumukh was published in 1870. Griesbach, of the Geological Survey of India visited the glacier snout in 1889 and made a sketch of the snout front showing Gaumukh located on the western side of the snout. Dr Auden of the Geological Survey mapped and photographed the glacier snout in 1935 and has, since, been followed by a number of teams from GSI and some other institutes in recent years. A comparative study of the photographs of the snout taken, from time to time, shows that the position of Gaumukh has been shifting from the western limits to the eastern limits of the snout expanse.

Birbal Sahni Institute of Paleobotany, Lucknow, has dated the trees that are growing over the old terminal moraines at Bhojbasa, about 12 kilometres downstream of the present Gaumukh to be about 415 years old. This would mean that the terminal moraines at Bhojbasa would be about five hundred years old, as some time gap must have occurred between the vacation by the glacier and growth of vegetation. Taking that as the base, Geological Survey of India teams have, more or less, regularly since 1935, been monitoring the snout of this glacier and, as a part of the monitoring activity, map of the snout front has been prepared at various times. Comparison of the snout positions between 1935 and 1996 has revealed that the glacier front, especially the position of the ice cave Gaumukh, has been constantly changing and the glacier has retreated by about 1,100 metres during the period of 61 years (1935 to 1996), that is, an average retreat of eighteen metres a year. A recent study, with the help of satellite images has revealed that the position of Gaumukh along the eastern limits has further retreated at an average of about 15 metres per year in 2001 and 2002. Observations also show that Raktavaran Nala (melt water stream from the Raktavaran group of glaciers) that had been flowing sub glacially till up to 2002 has eroded away the glacier ice on the eastern side and has now started flowing along the valley wall by passing the eroded glacier ice.

Recent publications have come out with the frightening prospect of this glacier vanishing from the surface of earth in the immediate future. One publication has gone to the extent of giving 2035 as the destiny day. The danger, however, may not be that imminent.

In the words of Bhagirath, “Ganga, one day shall be recalled to the heavens!” Reading between the lines, it connotes the fact that Bhagirath realised, thousands of years ago, that this glacial river having come from the skies (heaven) shall one day retreat to the skies. If we assume that this glacier will continue to retreat, say at the rate of 15 to 18 metres a year, as it is doing at present, even then it will take almost one and a half century for the glacier, so to say, to go back to the skies. Are we prepared for this eventuality?

(The writer isan anthropologist, author, traveler & activist who also runs a public walking group called Been There, Doon That?)